RESUMEN
BACKGROUND AND AIM: The aim of the present case-control study is to explore the effect of case mix on the relationship between glycated haemoglobin (HbA1c) and mortality in type 2 diabetic patients. METHODS AND RESULTS: A nested case-control study data set was generated from the cohort-study data set (n = 4140 type 2 diabetic outpatients) by sampling controls from the risk sets. Cases (n = 427) were compared with an equal number of controls chosen from those members of the cohort who were at risk for the same follow-up time of the case, matched for age (±3 years), sex, body mass index (BMI) (±2 kg m(-2)), duration of diabetes (±5 years), and Charlson's Comorbidity Score (CCS) (±1). The main predefined analysis was the comparison of cases and controls for proportion of patients with each HbA1c class (<6.5%, 6.5-7.4%, 7.5-8.4% and ≥8.5%). During a mean follow-up of 5.7 ± 3.5 years, 427 deaths were recorded. The lowest risk of death was observed in the HbA1c 6.5-7.4% category; a lower HbA1c was associated with a non-significant trend towards a higher risk. The risk associated with a low (<6.5%) HbA1c was significantly greater in patients who were insulin-treated than in the rest of the sample. CONCLUSIONS: The present study suggests that glycaemic targets should be individualised on the basis of the characteristics of each patient, considering age, co-morbidity and duration of diabetes. Caution should be used in prescribing insulin to reach near-normoglycaemia, particularly in older, frail patients.
Asunto(s)
Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/mortalidad , Hemoglobina Glucada/análisis , Medicina de Precisión , Factores de Edad , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , Comorbilidad , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Femenino , Anciano Frágil , Humanos , Hipoglucemiantes/efectos adversos , Insulina/efectos adversos , Italia/epidemiología , Modelos Logísticos , Masculino , Persona de Mediana Edad , Pronóstico , Medición de Riesgo , Factores de Riesgo , Factores de TiempoRESUMEN
AIMS: Aim of this case-control study is the assessment of the relationship between antihypertensive treatment and incidence of diabetes in an unselected cohort of subjects participating in a screening program for diabetes. METHODS: A case-control study nested within a cohort of nondiabetic subjects with a mean follow-up of 27.7 ± 11.3 months was performed, comparing 40 cases of incident diabetes and 160 controls matched for age, sex, body mass index, fasting plasma glucose, 2-h post-load glycemia, smoking and alcohol abuse. RESULTS: When considering antihypertensive treatment at enrolment, a lower proportion of cases was exposed to ACE-inhibitors/angiotensin receptor blockers (ACE-i/ARB) in comparison with controls. A non-significant trend toward a higher exposure to diuretics, which were mainly represented by thiazide diuretics, was observed in cases. In a multivariate analysis, including both ACE-i/ARB and diuretics, a protective effect of ACEi/ARB, and an increased risk with diuretics were observed. Similar results were obtained in alternative models, after adjusting for systolic and diastolic blood pressure at enrolment, diagnosis of hypertension, concurrent treatment with ß-blockers or calcium-channel blockers, and number of antihypertensive medications. CONCLUSIONS: Diuretics seem to be associated with a higher incidence of diabetes, whereas treatment with ACEi/ARB could have a protective effect.
Asunto(s)
Antihipertensivos/efectos adversos , Diabetes Mellitus/epidemiología , Hipertensión/tratamiento farmacológico , Adulto , Anciano , Inhibidores de la Enzima Convertidora de Angiotensina/efectos adversos , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Antihipertensivos/farmacología , Antihipertensivos/uso terapéutico , Estudios de Casos y Controles , Estudios de Cohortes , Diabetes Mellitus/inducido químicamente , Diuréticos/efectos adversos , Diuréticos/uso terapéutico , Femenino , Estudios de Seguimiento , Humanos , Hipertensión/epidemiología , Incidencia , Masculino , Persona de Mediana EdadRESUMEN
AIM: Some studies suggested that metformin could reduce cardiovascular risk to a greater extent than that determined by glucose reduction. Aim of the present meta-analysis is to assess the effects of metformin on the incidence of cardiovascular events and mortality. METHODS: An extensive search of Medline, EMBASE and the Cochrane Library (any date up to 31 October 2009) was performed for all trials containing the word 'metformin'. Randomized trials with a duration ≥52 weeks were included. A meta-regression analysis was also performed to identify factors associated with cardiovascular morbidity and mortality in metformin-treated patients. RESULTS: A total of 35 clinical trials were selected including 7171 and 11 301 participants treated with metformin and comparator, respectively, who had 451 and 775 cardiovascular (CV) events, respectively. Overall, metformin was not associated with significant harm or benefit on cardiovascular events (MH-OR 0.94[0.82-1.07], p = 0.34). A significant benefit was observed in trials versus placebo/no therapy (MH-OR 0.79[0.64-0.98], p = 0.031), but not in active-comparator trials (MH-OR 1.03[0.72-1.77], p = 0.89). Meta-regression showed a significant correlation of the effect of metformin on cardiovascular events with trial duration and with minimum and maximum age for inclusion, meaning that the drug appeared to be more beneficial in longer trials enrolling younger patients. It is likely that metformin monotherapy is associated with improved survival (MH-OR: 0.801[0.625-1.024], p = 0.076). However, concomitant use with sulphonylureas was associated with reduced survival (MH-OR: 1.432[1.068-1.918], p = 0.016). CONCLUSION: Available evidence seems to exclude any overall harmful effect of metformin on cardiovascular risk, suggesting a possible benefit versus placebo/no treatment. The observed detrimental effect of the combination with sulphonylureas deserves further investigation.
Asunto(s)
Enfermedades Cardiovasculares/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Angiopatías Diabéticas/tratamiento farmacológico , Hipoglucemiantes/administración & dosificación , Metformina/administración & dosificación , Enfermedades Cardiovasculares/mortalidad , Enfermedades Cardiovasculares/prevención & control , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/mortalidad , Angiopatías Diabéticas/mortalidad , Angiopatías Diabéticas/prevención & control , Femenino , Humanos , Hipoglucemiantes/farmacología , Masculino , Metformina/farmacología , Ensayos Clínicos Controlados Aleatorios como Asunto , Medición de RiesgoRESUMEN
BACKGROUND: The impaired response of glucagonlike peptide-1 (GLP-1) to meals in diabetic patients can contribute to the pathogenesis of impaired insulin secretion and post-prandial hyperglycemia. This study is aimed at the assessment of the relationship between meal-induced GLP-1 and post-prandial hyperglycemia in Type 2 diabetic patients. METHODS: Twenty-one drug-naïve Type 2 diabetic patients were studied. Blood glucose and active GLP-1 levels were measured 0, 30, 60, 90, and 120 min after a standard test meal. A continuous glucose monitoring (CGM) system was applied for the following 3 days. Nutrient intake at each meal was calculated on the basis of patients' food records. For each patient, post-prandial 120-min glucose incremental area under the curve (iAUC) was included in linear regression model exploring its relationship with total energy and carbohydrate intake, and the angular coefficient for total energy (EAC) and carbohydrate (CAC) was calculated. RESULTS: GLP-1 levels peaked 30 min after the test meal. Logarithmically transformed 60-min GLP-1 iAUC showed a significant inverse correlation with glycated hemoglobin (HbA1c) (p<0.01). A significant inverse correlation of 60-min GLP-1 iAUC was also observed with EAC and CAC (both p<0.01), meaning that patients with a lower GLP-1 response to the test meal had a higher increment of post-prandial glucose for each additional unit of total energy or carbohydrate intake. CONCLUSIONS: In Type 2 diabetic patients, a lower GLP-1 response to meals is associated with a higher HbA1c, and with a greater degree of meal-induced hyperglycemia, both in a meal test and during CGM in "real-life" conditions.
Asunto(s)
Glucemia/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Ingestión de Alimentos/fisiología , Péptido 1 Similar al Glucagón/metabolismo , Hiperglucemia/metabolismo , Periodo Posprandial/fisiología , Área Bajo la Curva , Automonitorización de la Glucosa Sanguínea , Femenino , Péptido 1 Similar al Glucagón/sangre , Hemoglobina Glucada/metabolismo , Humanos , Modelos Lineales , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND AND AIMS: Randomized clinical trials (RCTs) aimed at the assessment of the efficacy of lowering blood glucose in the prevention of diabetic complications have always failed to detect a significant effect on cardiovascular events. Aim of this meta-analysis is the assessment of the effects of improvement of glycemic control on the incidence of cardiovascular diseases in patients with type 2 diabetes. METHODS: The RCTs were included in this meta-analysis if: a) the between-group difference in mean HbA1c during the trial was at least 0.5%, b) they had a planned duration of treatment of at least 3 years, c) if they had a cardiovascular endpoint. Data for analysis were extracted independently by two observers and potential contrasts were resolved by a senior investigator. RESULTS: Five studies (17,267 and 15,362 patients in the intensive and conventional therapy groups, respectively) were included. Intensive treatment, which reduced mean HbA1c by 0.9% on average, was associated with a significant reduction of incident cardiovascular events and myocardial infarction (OR 0.89 [0.83-0.95] and 0.86 [0.78-0.93], respectively), but not of stroke or cardiovascular mortality (OR 0.93 [0.81-1.07] and 0.98 [0.77-1.23], respectively). In meta-regression analysis, a higher BMI duration of diabetes, and incidence of severe hypoglycaemia were associated with greater risk for cardiovascular death in intensive treatment groups. CONCLUSION: Intensified hypoglycaemic treatment in type 2 diabetic patients leads to a significant reduction of the incidence of myocardial infarction, while it does not affect the incidence of stroke and cardiovascular mortality. Hypoglycemia induced by intensified treatment could be associated with increased cardiovascular mortality.
Asunto(s)
Enfermedades Cardiovasculares/prevención & control , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Angiopatías Diabéticas/prevención & control , Hiperglucemia/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Enfermedades Cardiovasculares/mortalidad , Diabetes Mellitus Tipo 2/mortalidad , Angiopatías Diabéticas/mortalidad , Humanos , Hiperglucemia/mortalidad , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
AIM: The aim of this meta-analysis of randomized clinical trials (RCT) was to assess whether pioglitazone is also associated with increased cardiovascular risk, as recently reported for rosiglitazone. METHODS: RCT of pioglitazone were retrieved from Medline (any date up to 31 August 2007; English language only). Unpublished RCT were identified through http://www.clinicaltrials.gov or http://www.fda.gov websites, and results on cardiovascular outcomes were retrieved from investigators and/or sponsors, whenever possible. RCT were included in meta-analysis if pioglitazone was compared with other treatments (placebo, active comparators or no treatment) for at least 4 weeks. Ninety-four trials, 10 of which were unpublished, were retrieved; those included in the analysis, which excluded PROspective PioglitAzone Clinical Trial In MacroVascular Events (PROACTIVE), enrolled 11 268 and 9912 patients in the pioglitazone and comparator groups respectively. Data for analysis, extracted independently by two observers, included all-cause and cardiovascular mortality and incidence of non-fatal coronary events and heart failure. Proportions of outcome measures across treatment groups were compared by odds ratios (ORs) and 95% confidence interval. RESULTS: Pioglitazone was associated with reduced all-cause mortality [OR 0.30 (0.14-0.63); p < 0.05], with no relevant effect on non-fatal coronary events. The observed increase in incidence of non-fatal heart failure was not statistically significant [OR 1.38 (0.90-2.12)]. CONCLUSION: The use of pioglitazone does not appear to be harmful in terms of cardiovascular events and all-cause deaths.
Asunto(s)
Enfermedad Coronaria/inducido químicamente , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Insuficiencia Cardíaca/inducido químicamente , Hipoglucemiantes/efectos adversos , Tiazolidinedionas/efectos adversos , Anciano , Causas de Muerte , Enfermedad Coronaria/mortalidad , Enfermedad Coronaria/prevención & control , Insuficiencia Cardíaca/mortalidad , Humanos , Persona de Mediana Edad , Pioglitazona , Ensayos Clínicos Controlados Aleatorios como Asunto , Factores de Riesgo , Resultado del TratamientoRESUMEN
BACKGROUND: Recent evidence suggests that some hypoglycemic treatments could affect the incidence of malignancies. This study was aimed at the assessment of cancer-related mortality in type 2 diabetic patients treated with different hypoglycemic drugs. METHODS: A retrospective observational cohort study was performed on a consecutive series of 3002 type 2 diabetic outpatients. Cancer-related death was identified through the City Registry Office. For patients visited for the first time after January 1 (st), 2000, information on incidence of cancer was also available. RESULTS: During a mean follow-up of 4.3+/-2.5 years, 87 cases of cancer-related death were recorded, with a yearly incidence rate of 0.70%. Patients receiving secretagogues showed a significantly higher mortality than the rest of the sample (unadjusted OR [95%CI] 1.76 [1.15-2.69], p=0.009), which was maintained after adjustment for confounders (HR 2.29 [1.21-4.02], p=0.003). Conversely, no significant association of cancer-related mortality was observed with insulin sensitizers or exogenous insulin. In comparison with patients receiving no hypoglycemic treatment, those on secretagogue or insulin monotherapy showed a higher cancer-related mortality (HR 2.25 [1.10-4.78], p=0.034 and HR 2.11 [1.01-4.50], p=0.048, respectively). The effect of treatments on incidence of malignancies was similar to that observed on cancer-related death. CONCLUSIONS: Insulin secretagogues and, to a lesser extent, exogenous insulin, appear to be associated with increased mortality for cancer, even after adjustment for multiple confounders. This issue deserves further investigation through epidemiological studies on larger samples of patients.
Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/efectos adversos , Insulina/metabolismo , Neoplasias/mortalidad , Administración Oral , Anciano , Estudios de Cohortes , Diabetes Mellitus Tipo 2/mortalidad , Femenino , Humanos , Hipoglucemiantes/administración & dosificación , Secreción de Insulina , Masculino , Persona de Mediana Edad , Neoplasias/complicaciones , Estudios RetrospectivosRESUMEN
Cholera toxin (CT) injected ip on day 1 (day of ovulation) of the 4-day hamster estrous cycle, when circulatory progesterone is high and estrogen low, induced a massive uterine decidual reaction, a progesterone-dependent growth normally triggered by the implanting blastocyst. However, CT injected ip on day 3, when circulatory estrogen is high and progesterone low, did not induce a decidual reaction but, instead, intensified the effects of estrogen (stromal edema and stimulation of the mucosa). These cycle day effects were reproduced in one uterine horn injected intraluminally with CT, but not in the other horn of the same animal given solvent alone as a control. The intrauterine injection of CT had no effect on the concentration of serum estrogen or progesterone. The decidual reaction resulting from intrauterine injection of CT on day 1 was accompanied by increases in estrogen receptor (femtomoles per mg DNA) in both cytoplasm and nucleus. In long term ovariectomized hamsters, an ip or intrauterine injection of CT induced only histological effects of estrogen (stromal edema and mucosal mitosis) without affecting circulatory estrogen. These estrogenic effects were accompanied by increases in receptors for estrogen and progesterone in both cytoplasm and nucleus. CT injected ip into ovariectomized hamsters primed with estrogen intensified the stromal edema and mucosal mitosis and resulted in progesterone and estrogen receptor levels equal to or greater than those after the administration of CT or estrogen alone. When progesterone was included in the priming (estrogen + progesterone + CT), all receptor levels were decreased, and a massive decidual reaction resulted. Thus, the induction of estrogen receptor by CT may have been the primary event that triggered the decidual reaction. Whether CT-induced estrogen receptor is mediated by cAMP, a known mediator of CT, remains to be determined.
Asunto(s)
Toxina del Cólera/farmacología , Decidua/fisiología , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismo , Útero/fisiología , Animales , Cricetinae , Decidua/efectos de los fármacos , Femenino , Mesocricetus , Mitosis/efectos de los fármacos , Tamaño de los Órganos/efectos de los fármacos , Embarazo , Receptores de Estrógenos/efectos de los fármacos , Receptores de Progesterona/efectos de los fármacos , Útero/citología , Útero/efectos de los fármacosAsunto(s)
Bioquímica/historia , ADN , Biología Molecular/historia , Historia del Siglo XX , Estados UnidosRESUMEN
The distribution of galanin immunoreactive (Gal/IR) neurons was investigated in the gastrointestinal (GI) tract of the lizard Podarcis s. sicula. The indirect immunofluorescence method, image analysis and confocal analysis were applied to cryostat sections and whole mount preparations. Gal/IR nerve fibers and cell bodies were found throughout the lizard GI tract in the myenteric plexus, circular muscle layer and mucosa. These nerve structures decreased caudally. The stomach revealed a denser reactive nerve population than elsewhere. The projections of Gal/IR neurons were detected in the myenteric plexus of lizard gut using a confocal microscope which analyzed the immunoreactive material on the proximal and distal sides of muscle myotomies. An accumulation of Gal/IR material on the oral side of the myotomies demonstrated the oral-to-anal projection of Gal containing nerve structures. Based on our results, it can be hypothesized that Gal/IR neurons of the lizard digestive tract belong to the inhibitory descending pathway, which in most vertebrates is responsible for gut peristalsis regulation.
Asunto(s)
Canal Anal/inervación , Sistema Digestivo/inervación , Galanina/análisis , Lagartos/fisiología , Neuronas/fisiología , Animales , Sistema Digestivo/citología , Fenómenos Fisiológicos del Sistema Digestivo , Técnica del Anticuerpo Fluorescente Indirecta , Inmunohistoquímica , Boca/inervación , Vías Nerviosas/fisiologíaRESUMEN
The distribution of nicotinamide adenine dinucleotide phosphate (NADPH)-d neurons and their relationship with nitric oxide synthase (NOS), vasoactive intestinal polypeptide (VIP), pituitary adenylate activating polypeptide (PACAP) and galanin (Gal) were examined in the gastrointestinal (GI) tract of the pigeon Columbia livia. NADPH-d-histochemistry, indirect immunofluorescence and confocal analysis were applied to cryosections. Western blot analysis was also applied on pigeon gut. NADPH-d neurons were found throughout the pigeon GI tract and they were evident in the myenteric, circular muscle and submucous plexuses. Positive varicose nerve fibres were also distributed within the longitudinal muscle layers and in the lamina propria of the mucosa. The stomach was the segment richest in positivities. The copresence VIP/Gal/NOS as well as PACAP/VIP were revealed in some NADPH-d-neurons. We suppose that the nitrergic nerve population of the pigeon GI tract belong to the muscle motility regulation as an inhibitory descending nerve pathway. Moreover the presence of VIP, Gal and PACAP in some NADPH-d-containing neurons enhances the inhibitory actions of these neurotransmitters whereas PACAP and Gal role is actually unknown.
Asunto(s)
Sistema Digestivo/enzimología , Sistema Digestivo/inervación , NADPH Deshidrogenasa/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Óxido Nítrico Sintasa/metabolismo , Animales , Columbidae , Sistema Digestivo/química , Sistema Nervioso Entérico/química , Sistema Nervioso Entérico/enzimología , Galanina/metabolismo , Microscopía Confocal , Microscopía Fluorescente , Neuropéptidos/metabolismo , Óxido Nítrico Sintasa de Tipo I , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa , Péptido Intestinal Vasoactivo/metabolismoRESUMEN
By means of immunochemistry and immunohistochemistry, we investigated in the gut of teleostean species the presence and localization of three neurotrophins: nerve growth factor (NGF), brain derived neurotrophic factor (BDNF) and neurotrophin (NT)-3. In all studied species both NGF- and NT-3-like immunoreactivity (IR) were present in the enteric nervous system, while BDNF-like IR was never detected. More in particular, both NGF and NT-3-like IR were detected in neurons of small and large intestine, while only NT3-like IR was also observed in stomach plexuses. Furthermore, Western blot analysis revealed the presence of molecules immunoreactive to NGF and NT-3, which weight were very similar to those of mammalian corresponding neurotrophins. These results extend to teleost species the presence and distribution of NGF- and NT-3-like IR in the enteric nervous system, suggesting a well-preserved presence of these substances in the gut during vertebrate phylogenesis.
Asunto(s)
Sistema Digestivo/metabolismo , Peces/metabolismo , Factores de Crecimiento Nervioso/metabolismo , Animales , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Inmunohistoquímica , Factor de Crecimiento Nervioso/metabolismo , Neurotrofina 3/metabolismo , Especificidad de la EspecieRESUMEN
The occurrence and distribution of Trk proteins, which are the high-affinity signal-transducing receptors for neurotrophins, have been investigated in earthworms (Eisenia foetida) using polyclonal antibodies which map within their catalytic domain. Western-blot analysis identified major protein bands whose estimated molecular masses were consistent with those of the full-length Trk proteins in vertebrates. Specific immunoreactivity for TrkA-, TrkB-, and TrkC-like was observed in neuronal populations of the dorsal cerebral, subpharyngeal and ventral cord ganglia. Furthermore, TrkA-like immunoreactivity was observed in subcutaneous neurons and nerve fibers between muscle layers in the peripheral nervous system. TrkB- and TrkC-like immunoreactivity was observed in the gut innervation. Non-neuronal expression of TrkB and TrkC proteins was found in epidermal cells, and TrkC-like immunoreactivity was detected in the gut epithelium.
Asunto(s)
Neuronas/metabolismo , Oligoquetos/metabolismo , Proteínas Tirosina Quinasas Receptoras/biosíntesis , Animales , Western Blotting , Sistema Digestivo/inervación , Sistema Digestivo/metabolismo , Inmunohistoquímica , Músculos/inervación , Músculos/metabolismo , Mapeo Peptídico , Sistema Nervioso Periférico/metabolismo , Receptor de Factor Neurotrófico Ciliar , Receptor trkA/biosíntesis , Receptor trkC , Receptores de Factor de Crecimiento Nervioso/biosíntesisRESUMEN
Testosterone receptors (AR) are present in the liver of the female green frog, Rana esculenta, which resolve into two fractions (A and B) by ion-exchange chromatography. Fraction A is primarily located in the nuclei, fraction B predominates in the cytosols, and both fractions show a high affinity and specificity for testosterone. Liver AR fraction levels vary dramatically during the frog sexual cycle. Fraction A levels are high only when the liver is engaged in vitellogenin production and the plasma testosterone levels are high: they are maximal when aromatase activity is most intense. Fraction B levels are high when the liver is not producing vitellogenin and the plasma testosterone levels are minimal. In addition, in vivo experiments carried out on ovariectomized females treated with testosterone show that testosterone induces both fraction A and liver aromatase activity. This induction may be a step in the process that allows the liver to obtain estrogen from plasma testosterone which induces vitellogenin synthesis.
Asunto(s)
Aromatasa/biosíntesis , Hígado/enzimología , Receptores Androgénicos/metabolismo , Animales , Núcleo Celular/metabolismo , Cromatografía por Intercambio Iónico , Citosol/metabolismo , Inducción Enzimática , Femenino , Ovariectomía , Isoformas de Proteínas , Rana esculenta , Receptores Androgénicos/química , Testosterona/sangre , Testosterona/farmacologíaRESUMEN
The distribution of nicotinamide adenine dinucleotide phosphate reduced diaphorase (NADPH-d) containing neurons was examined in the oviduct of the lizard Podarcis s. sicula and the relationship between these neurons and 17beta-estradiol hormone was studied. NADPH-d-histochemistry and indirect immunofluorescence method were applied to cryostat sections. NADPH-d-nerve structures were found throughout the oviduct. Positive neurons were primarily located in the reproductive oviduct, and were more numerous in the intermuscular and circular muscle layers than in the mucosa. The vagina revealed a reactive nerve population denser than elsewhere. The NADPH-d-positive neurons densities and the 17beta-estradiol plasma levels coincided throughout the lizard sexual cycle. In addition, after 17beta-estradiol treatments, non-reproductive lizards showed an increase of NADPH-d neurons. We suppose that nitric oxide (NO) neurons play an estrogen-dependent role in the oviduct muscle motility.
Asunto(s)
Estradiol/farmacología , Lagartos/crecimiento & desarrollo , NADPH Deshidrogenasa/análisis , Neuronas/química , Oviductos/inervación , Animales , Estradiol/sangre , Femenino , Inmunohistoquímica , Estadios del Ciclo de Vida , NADPH Deshidrogenasa/inmunología , Óxido Nítrico Sintasa/análisis , Óxido Nítrico Sintasa/inmunología , Contracción Uterina , Vagina/inervaciónRESUMEN
The distribution of neurons containing galanin immunoreactivity (Gal/IR) has been detected in the oviduct of the lizard Podarcis s. sicula during the main phases of its sexual cycle and after 17beta-estradiol treatment. Indirect immunofluorescence technique was applied both to cryostatic sections and whole mount preparations, and Western blot analysis, with an antibody directed against mammalian galanin (Gal), was performed with lizard oviduct extracts. Colocalization of Gal with vasoactive intestinal polypeptide (VIP) was also studied as well as Gal effects on egg deposition. In the quiescent oviduct of non-reproductive females, scanty Gal/IR fibres were found in the uterine-vaginal segment. During the reproductive period a gradual increase of positive nerve fibres and cell bodies were found distally in the lizard oviduct and the vagina revealed a reactive nerve population denser than elsewhere. Gal-IR nerve structures were present either in the musculature or mucosa and in the intermuscular layer they were organized in a nerve network. In the oviduct of non-reproductive females, 17beta-estradiol administration induced a significant increase of neurons containing Gal/IR. This hormone could be involved in the egg laying by means of galanin action and this hypothesis is supported by the induction of premature oviposition in pre-ovulatory females after Gal administration. Western blot analysis validates this peptide as true Gal, recognising one protein band with a molecular weight (3.2 kDa), similar to that of porcine Gal. Double labelling studies showed the co-presence of Gal and VIP in some neurons.
Asunto(s)
Estradiol/farmacología , Galanina/análisis , Lagartos/fisiología , Neuronas/química , Oviposición/efectos de los fármacos , Péptido Intestinal Vasoactivo/análisis , Animales , Western Blotting , Recuento de Células/efectos de los fármacos , Femenino , Galanina/farmacología , Inmunohistoquímica , Peso Molecular , Membrana Mucosa/inervación , Músculo Liso/inervación , Red Nerviosa/citología , Red Nerviosa/efectos de los fármacos , Neuronas/citología , Neuronas/efectos de los fármacos , Oviductos/anatomía & histología , Oviductos/efectos de los fármacos , Oviductos/crecimiento & desarrollo , Oviductos/inervación , Péptidos/farmacología , Factores de Tiempo , Útero/inervación , Vagina/inervaciónRESUMEN
ensp;The distribution and colocalisation of nicotinamide adenine dinucleotide phosphate reduced-diaphorase (NADPH-d)-/nitric oxide synthase (NOS)-containing (nitrergic) neurons in the innervation of the duck ureter have been studied using histochemistry and immunohistochemistry. Quantitative analysis showed that nitrergic neurons made up 60% and 70% of the total intramural and adventitial neuronal populations, respectively. About 40% of intramural nitrergic neurons expressed VIP-immunoreactivity, and about 75% of nitrergic adventitial neurons expressed TH-immunoreactivity. The density of nitrergic adventitial neurons was significantly greater in the lower tract than in the upper and intermediate tracts. Nerve lesioning experiments showed that the majority of ureteral nitrergic innervation was extrinsic in origin; nitrergic adventitial neurons primarily projected caudocranially, whereas NOS-immunoreactive and NOS-/VIP-immunoreactive intramural neurons primarily projected craniocaudally. These findings suggest that, in birds, the nitrergic innervation plays a role in ureteral functions such as epithelial mucosecretion, muscular motility, and the closing and/or opening of the ureteral papilla.
Asunto(s)
Sistema Nervioso Autónomo/enzimología , Patos/anatomía & histología , NADPH Deshidrogenasa/metabolismo , Neuronas/enzimología , Óxido Nítrico Sintasa/metabolismo , Uréter/inervación , Animales , Recuento de Células , Desnervación , Vías Eferentes/anatomía & histología , Femenino , Ganglios Simpáticos/citología , Masculino , Neuronas/citología , Óxido Nítrico Sintasa de Tipo I , Tirosina 3-Monooxigenasa/metabolismo , Uréter/cirugía , Péptido Intestinal Vasoactivo/metabolismoRESUMEN
The distribution of neurons containing the enzymes NADPH-diaphorase (NADPH-d) and nitric oxide synthase (NOS) has been studied in the gastrointestinal tract of lizard (Podarcis s. sicula) and snake (Thamnophis sirtalis). The techniques employed were the NADPH-d/nitroblue tetrazolium histochemical method, and the indirect immunofluorescence applied to cryostat sections and to whole-mount preparations. The colocalization of NADPH-d with NOS, with vasoactive intestinal polypeptide (VIP) and with galanin (Gal) was also studied, and a Western blot analysis using an antibody directed against mammalian Gal was performed on lizard stomach extracts. NADPH-d positive nerve cell bodies and fibres were found in the myenteric and submucous plexuses throughout the gastrointestinal tract of both reptiles. These nerve structures were also present in the other intramural nerve plexuses, although in smaller quantities. Both in lizard and snake, the stomach revealed a positive nerve population that was more dense than elsewhere in the gut. The population of the NADPH-d-positive neurons observed in the lizard was larger than that observed in the snake. The distribution of both populations was similar to those that have been described in the gut of several mammalian and non-mammalian vertebrates. Both in lizard and snake, a one-to-one correspondence was noted between NOS- and NADPH-d-containing nerve cell bodies, and the nitrergic neurons containing Gal appeared to be more numerous than those containing VIP. Western blot analysis recognised a single band with a molecular weight (3.4 kDa) very similar to that of porcine Gal. It is hypothesised that at least some of the nitrergic neurons of the lizard and snake gut are inhibitory motor neurons innervating the circular smooth musculature. In addition, the colocalization of NOS and VIP in neurons enhances their inhibitory action. The role of the neurons containing both NOS and Gal remains unknown.
Asunto(s)
Sistema Digestivo/enzimología , Sistema Digestivo/inervación , Galanina/metabolismo , NADPH Deshidrogenasa/metabolismo , Neuronas/enzimología , Óxido Nítrico Sintasa/metabolismo , Péptido Intestinal Vasoactivo/metabolismo , Animales , Western Blotting , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Lagartos , Masculino , Plexo Mientérico/citología , Plexo Mientérico/enzimología , Neuronas/citología , Óxido Nítrico Sintasa de Tipo I , SerpientesRESUMEN
The Authors report a case of choledochal cystic dilatation and examine this particular anomaly of the main biliary duct analysing the complex classification. After a brief review of the embryology of the hepato-pancreatic ring, etiopathogenetic theories, clinic characteristics, as well as diagnostic and therapeutic possibilities for this affection are taken into account. It is concluded that the best therapeutic choice should be always based on an accurate evaluation of the anatomo-pathological conditions in each single case.